Editor's note: Each day until the NFL Draft begins on Thursday night, Tom Pelissero is breaking down the Minnesota Vikings' roster by position, based on observations of games and practice, tape studies and interviews with NFL coaches and scouts.

Kalil (6-foot-7, 295 pounds) and Loadholt (6-8, 343) are locked in as the tackles for the long haul, the former a Pro Bowl selection as a rookie and the latter signed to a four-year, $25 million contract last month. Sullivan (6-4, 301) appears over his early-career injury issues and continues to ascend among the NFL's top centers. The question marks are at guard, where the Vikings moved on from longtime starters Steve Hutchinson and Anthony Herrera a year ago and still can't be certain they've found their successors. Johnson (6-4, 305) slid inside after Kalil's arrival and fared better at left guard. But he agreed to renegotiate the last non-voidable year of his contract last month -- a nod to the reality $4.35 million is too much to pay for average performance at the position. (He's now scheduled to make $3.25 million.) Coach Leslie Frazier said at the NFL meetings that Fusco (6-4, 306) enters the offseason as the "named starter" at right guard despite showing in 2012 how raw he remains. He'll face competition in camp -- though perhaps not from anyone on the current roster. Berger (6-5, 315) got a $65,000 signing bonus on his minimum salary benefit deal and remains a valuable multiple-position backup. Olsen (6-5, 312) signed for $20,000 after not receiving a restricted tender in Indianapolis, where he started five games over two seasons. Kropog (6-6, 308) might have the best shot to get on the field, considering the Vikings quietly gave him a raise on the practice squad in November to make sure he didn't depart before they could put him on the 53-man roster. But he has appeared in only seven NFL games (all in Tennessee) since the Titans drafted him in the fourth round out of Tulane in 2009. Perhaps he battles for Schwartz's old swing tackle job against Love (6-4, 315), who was inactive throughout his rookie season in 2011 and missed last year with a torn pectoral muscle that required surgery. Murphy (6-7, 295) has the feet for left tackle and should benefit from the offseason strength program that begins on Monday. Ditto Holmes (6-4, 312), who bounced on and off the practice squad as a rookie.

Draft outlook

The Vikings have a lot of resources invested in the offensive line and greater needs elsewhere. Also, it's worth remembering Fusco is only two years removed from being a center at Division II Slippery Rock. He was always going to be a project. That said, the Vikings figure to target another guard -- maybe even as early as Round 1, depending on whether they believe an athlete such as Oregon's Kyle Long could be a difference-marker. More likely, they'll address that sometime between Rounds 2 and 5, unless they're convinced their relatively untested depth is sufficient insurance. That Johnson may be gone after the season only raises the urgency to accumulate options.